1. Field of the Invention
The present invention relates to a color filter used in a liquid crystal display and a method for manufacturing the same.
2. Description of the Related Art
In a liquid crystal display, a transparent substrate on a color filter side and a substrate on a liquid crystal driving side are opposed to each other, and a liquid crystal compound is encapsulated therebetween to form a thin liquid crystal layer. And a display is carried out by selectively changing the quantity of transmissive light or reflective light from the color filter by electrically regulating the liquid crystal alignment in the liquid crystal layer by the substrate on the liquid crystal driving side.
Such liquid crystal display is driven by various driving systems such as a static driving system, a simple matrix system and an active matrix system. However, in recent years, color liquid crystal displays using a liquid crystal panel of the active matrix system or simple matrix system are rapidly spreading as flat displays in personal computers and portable information terminals.
FIG. 3 shows one example of a liquid crystal display panel of the active matrix system. A liquid crystal display 101 has a structure wherein: a color filter 11 and a TFT array substrate 12, which is the substrate on a liquid crystal driving side, are opposed to each other with a gap 13 of about 1 to 10 μm therebetween; this gap 13 is filled with a liquid crystal L; and around thereof is sealed with a sealing material 14. The color filter 11 has a structure wherein, on a transparent substrate 15, a black matrix layer 16 formed in a predetermined pattern for light shielding the boundaries among pixels, pixel parts 17 of which a plurality of colors (usually three primary colors of red (R), green (G) and blue (B)) aligned in a predetermined alignment for forming each pixel, a protective film 18, and a transparent electrode film 19 are laminated in this order from the side of the transparent substrate.
On the other hand, the TFT array substrate 12 has a structure wherein a TFT element is aligned on a transparent substrate, and a transparent electrode film 21 is provided. An alignment film 20 is provided on the inner side of the color filter 11 and on the opposing TFT array substrate 12. A color image is obtained by regulating the light transmittance of the liquid crystal layer placed on the back of a pixel colored in each color.
Generally, the transparent electrode provided on the TFT array substrate side is formed for each pixel part with a width wider than that of the pixel part of the color filter. However, for example, when the edge side of the light shielding part, that is, the boundary between the light shielding part and the pixel part, is ragged (ragged refers to a state wherein a pattern is rough around the edges), the width of the pixel part is enlarged so that the pixel part partially exceeds from the opposing transparent electrode. In this case, voltage is not applied to the liquid crystal on the pixel part, which exceeds from the opposing transparent electrode, so that there is a problem of light leakage from this part.
Inspection of defects such as scratches and unevenness of a pixel part in a color filter is carried out by irradiating light having predetermined intensity from the backside of the color filter and measuring the intensity of light quantity transmitted through each pixel part. However, when the edge side of the light shielding part is ragged, there is a problem that, since the intensity of light quantity is changed, defects (pseudo-defects) are detected even if there are no defects in the pixel part.